1. Field of the Invention
The present invention relates to a magnetic transfer holder which is used in magnetic transfer of information, from a master information carrier that bears the information, to a slave medium, and a magnetic transfer device.
2. Description of the Related Art
Magnetic transfer is the subject matter of the present invention. The object of magnetic transfer is to transfer and record a magnetization pattern corresponding to information, which is borne by a master information carrier, to a slave medium. This is accomplished by applying a transfer magnetic field in a state in which the master information carrier (patterned master) having a magnetic layer at least on its surface, in which a transfer pattern such as servo signals is formed as an uneven pattern or as embedded structures, contacts the slave medium which has a magnetic recording portion.
When the foregoing slave medium is a discoid medium such as a hard disk or a high-density flexible disk, the transfer magnetic field is applied by arranging a magnetic field application device comprising an electromagnet device or a permanent magnet device on one or both sides of the contact body comprising the slave medium and the master information carriers, in a state in which the discoid master information carriers contact a single side or both sides of this slave medium.
In order to improve transfer quality in this magnetic transfer, how uniformly the slave medium and the master information carrier contact each other is an important issue. That is, when there is a contact fault, an area receiving no magnetic transfer is caused. When magnetic transfer is not performed, signal drop-outs arise in the magnetic information transferred to the slave medium, and the signal quality level deteriorates. In this regard, when the recorded signal is a servo signal, a tracking function is not fully obtained and reliability is decreased.
In this regard, in the magnetic transfer as above, it is favorable that the master information carrier and the slave medium are housed inside of a magnetic transfer holder having a holder on a first side and a holder on a second side, that face and contact each other, in order to obtain uniform contact over the entire contact area (for example, refer to U.S. Patent Laid-Open No. 20020030909).
However, there has been a problem that obtaining close contact over the entire contact area is difficult due to a difference of flatness among the master information carrier, the slave medium, and the holder. Therefore, it has been proposed that an elastic body should be interposed when housing the master information carrier and the slave medium.
However, when magnetic transfer was performed by using a holder tightly holding a contact body comprising the master information carrier and the slave medium via the elastic body, damage or deformation occurred to the edges of the master information carrier and the slave medium. This was because pressure was intensively applied onto the outer and inner peripheries of the slave medium and the master information carrier when applying pressure to improve contact between the slave medium and the master information carrier. Further, at portions slightly inward from the outer and inner peripheral edges, some areas receiving low pressure were generated, wherein the signal quality level deteriorated.